The long term goal of this project is to provide an active ingredient for topical treatment of skin diseases, especially psoriasis, acne, eczema, and atopic dermatitis. The specific aim is to (1) develop the chemistry for isolating a species of polar lipid from marine algae that contain high concentrations of eicosapentaenoic acid (EPA), (2) identify the structure of the product by chemical and spectral means, and (3) test the effectiveness of this product, which will carry the tradename DermEPA, on cell proliferation and inflammation on human skin grafted to nude mice, using radiotracer technology. The technical innovation is isolation, for the first time, of a molecular species of lipid from algae that may be a superior topical delivery system of EPA. The process will be considered safe by the Food and Drug Administration for marketing DermEPA as an ethical drug. The diseases targeted affect approximately 14 million people in the United States.